Comment by CharlesW
2 years ago
> There just isn’t something better (and free) to replace it yet.
Apple's ALAC (Apple Lossless Audio Codec) format is an open-source and patent-free alternative. I believe both ALAC and FLAC support up to 8 channels of audio, which allows them to support 5.1 and 7.1 surround. https://en.wikipedia.org/wiki/Apple_Lossless_Audio_Codec#His...
These are distribution formats, so I'd be surprised if there were demand for floating-point audio support. And in contexts where floating point audio is used, audio size is not really a problem.
When FLAC compresses stereo audio, it does a diff of the left and right channels and compresses that. This often results in a 2x additional compression ratio because the left and right channels are tightly correlated.
Unless things have changed substantially and I missed it, FLAC does not do similar tricks for other multichannel audio modes. Meaning that for surround sound, each channel is independently compressed and it is unable to exploit signal correlation between channels.
Proprietary formats like Dolby on the other hand do support rather intelligent handling of multichannel modes.
FLAC is not solely a distribution format. Indeed as a distribution format it sucks in a number of ways. It is chiefly used as an archival format, and would in fact be ideal as a mastering format if these deficiencies Could be addressed.
In what ways does flac suck for distribution? All the music I download from Bandcamp is in that format, it works great for me.
It could be much smaller, maybe 2-3x better compression. Better support for surround sound / multichannel audio. If an AAC stream were used for the lossy predictive stage, then existing hardware acceleration could be used for energy efficient playback.
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